Akira Miyawaki (宮脇 昭, Miyawaki Akira; 29 January 1928 – 16 July 2021) was a Japanese botanist and an expert in plant ecology who specialized in seeds and natural forests. He was active worldwide as a specialist in natural vegetation restoration of degraded land. He was particularly known for his studies of reforestation using pocket forests, often called Miyawaki forests after him.

He was professor emeritus at Yokohama National University and director of the Japanese Center for International Studies in Ecology since 1993. He received the Blue Planet Prize in 2006.

Beginning in the 1970s, Miyawaki advocated for the restoration of natural forests. In 1992, he said he believed that the Earth Summit in Rio de Janeiro failed to emphasize the protection of native forests, most of which continued to decline.

Miyawaki observed trees that traditionally grew around temples, shrines, and cemeteries in Japan, such as the Japanese blue oak, Castanopsis cuspidata, bamboo-leaf oak, Japanese chestnut trees, and Machilus thunbergii. He believed that they were relicts of the primary forest. Meanwhile, he noted that trees such as Japanese cedar, cypress and larch pine, supposedly native to Japan, had been introduced into Japan over centuries by foresters to produce timber. Miyawaki reflected on the consequences of the change in composition and structure of most Japanese forests, most of which do not contain solely their original natural vegetation.

He calculated that only 0.06% of contemporary Japanese forests were indigenous forests. Contemporary forests, created according to forestry principles, in his opinion, are neither the most suitable candidates to address climate change nor the most resilient vegetation for the geo-bioclimatic conditions of Japan.

Using the concept of potential natural vegetation, Miyawaki developed, tested, and refined a method of ecological engineering today known as the Miyawaki method to restore native forests from seeds of native trees on very degraded soils that were deforested and without humus. With the results of his experiments, he restored protective forests in over 1,300 sites in Japan and various tropical countries, in particular in the Pacific region in the form of shelterbelts, woodlands, and woodlots, including urban, port, and industrial areas. Miyawaki demonstrated that rapid restoration of forest cover and soil was possible by using a selection of pioneer and secondary indigenous species that were densely planted and provided with mycorrhiza.

Miyawaki studied local plant ecology and used species that have key and complementary roles in the normal tree community.

Miyawaki was primarily a botanist who specialized in plant ecology and seeds, who wrote a thesis on the subject in the Department of Biology at the University of Hiroshima. He conducted field research in various parts of Japan while working as a research assistant at the Yokohama National University, and continued his studies at the University of Tokyo.